1. Field of the Invention
The present disclosure relates to a semiconductor device and more particularly relates to a semiconductor device having a high efficiency of heat dissipation and a manufacturing method for the semiconductor device.
2. Description of Related Art
As for semiconductor components including high-power semiconductor elements (for example, semiconductor light-emitting elements for a vehicle), it is important to efficiently dissipate heat generated by the semiconductor elements during use. Accordingly, a heat dissipation member comprising a material having high heat conductivity is mounted on the semiconductor component to improve heat dissipation. In the semiconductor component, a ceramic substrate having good heat conductivity is employed for a substrate on which the semiconductor element is disposed (see Patent Literatures 1 to 3: Japanese Unexamined Patent Application Publication No. 2009-194275, Japanese Unexamined Patent Application Publication No. 2013-055218, and Japanese Unexamined Patent Application Publication No. 2010-166019). When the semiconductor component is mounted on the heat dissipation member, the ceramic substrate of the semiconductor component is bonded to the heat dissipation member. It is known that soldering (Patent Literatures 1 and 2) or silver paste (Patent Literature 3), for example, is employed as a bonding method in this case,. Also, as another method for joining a plurality of members, a low-temperature bonding method has been known (Patent Literature 4: Japanese Unexamined Patent Application Publication No. 2008-207221). In the low-temperature joining method, metal films are formed on a bonding surface of each member in a vacuum, and a plurality of members can be bonded by contacting the metal films with each other. It is expected that using the low-temperature joining method for bonding the semiconductor component to the heat dissipation member allows for improving a heat dissipation performance.
In the bonding methods disclosed in Patent Literatures 1 to 3, the heat conductivity of solder or silver paste may not be sufficiently high, and an efficiency in dissipating heat from the semiconductor component to the heat dissipation member may not be sufficient. In the low-temperature bonding method disclosed in Patent Literature 4, the semiconductor component and the heat dissipation member are bonded with a metal material having high heat conductivity, so that an efficiency in dissipating heat from the semiconductor component to the heat dissipation member can be high, compared with the efficiencies in Patent Literatures 1 to 3. However, further improvement in heat dissipation has been required because of an increase in the amount of generated heat according to an increase in light output of the semiconductor element.